I don't see the key point: the two things (trusting the remote storage and the tool) are rather independent for me. I already trust probably billions lines of c

I don't see the key point: the two things (trusting the remote storage and the tool) are rather independent for me. I already trust probably billions lines of code which handle my data (basically, every program installed on my system). I don't trust them because I checked all of them, but because I know that the same lines are used by many other people, some of which have actually read parts of them. There is a global trust repository to which every programmer contributes a little bit and every user benefits a little bit. For this reason, I find more trustworthy a project already used and developed by many people, like borg. I didn't just take that for granted, of course: I read the documentation (which, in the case of borg, is very clean and extensive), I looked how it work, I even looked a part of the source code, and I was satisfied. And all of this has nothing to do with where I am putting that data in the end. On the other hand, missing features in the name of small code size is not a great advantage, if those missing features make my backup less reliable or quick or compact. And maybe I end up backing up less stuff because (say) the simple tool does not handle deduplication or compression as effectively as the complicated one, and so is not viable for me. This would be a net loss. Be careful, I am just saying my perspective. You have, of course, the entire right to decide what are your priorities and which tool is better for you.